On Fresh-water Crustacea. By Robert Gurney. "' 303 



This list of species recorded from Algeria and Tunisia is an 

 extensive one compared to any list that could be compiled for any 

 other part of Africa. The great majority of these species were 

 taken in the Tell or coast region, mainly in the neighbourhood of 

 Bone, but scattered observations have been made all over the 

 country from Oran to Tunis and as far south as Ouargla. 



The close connection existing between both the fauna and flora 

 of North Africa and those of the southern parts of Europe has 

 been abundantly demonstrated by many authors, and the conclu- 

 sions of the botanists and zoologists are borne out by those of 

 geologists. It is not, Jtherefore, to be expected that the Crustacea 

 should do otherwise than confirm the generally accepted opinion. 

 Furthermore, the Entomostraca, with their generally wide, and 

 yet often perplexing distribution, are not by any means a good 

 group from which to draw zoogeographical evidence. It is, how- 

 ever, remarkable, in view of their immense powers of dispersal, 

 that they do in fact point in the clearest possible way to the 

 independence of North Africa from the rest of the continent, and 

 its zoological affinity with Europe. The only species which, 

 outside Numidia, are found only in Southern Africa, are Apus 

 numidicus Grube and Streptocephalus ruhricaudatus Klunz. The 

 latter really hardly affects the question, as it has only been found 

 in Algeria between Ouargla and Temassinim, near the boundary 

 of the Pakearctic and Ethiopian regions. A peculiar feature of 

 the Entomostracan fauna is the presence of certain species 

 hitherto found only in Asia or Australia. These are Diaptomus 

 incrassatus Sars, which is recorded only from Central Asia, Dacty- 

 lopusiajugurtha Blanch, and Rich, from Siam, and Ilyocypris austra- 

 lieusis Sars from Queensland and Ceylon. Ceriodaphnia dubia 

 Rich, is found in Sumatra, New Zealand, Chili, Patagonia, and 

 Tierra del Fuego, but not in South Africa as yet. 



The countries bordering the Western Mediterranean have 

 faunistic relations which have led Dr. Forsyth Major to unite 

 them in a province called by him " Tyrrhenis,"* and it is a char- 

 acteristic of this province that many of its representative species r 

 either existing or extinct, have Oriental or South American 

 affinities.t The species just mentioned provide further evidence 

 of such affinity. Further, the species of Diaptomus which I have 

 called D. numidicus, seems to be most nearly related to D. stein- 

 dachneri from Albania, and D. drieschi from Ceylon. I), ingens is 

 related to the Spanish D. rovbaui and to D. amblyodon, which 

 extends from Austria to Siberia. 



The Entomostraca of Numidia indicate, therefore, an intimate 

 connection between North Africa and Western Europe, and suggest 



* See R. F. Scharff, European Animals, Loudon, 1907, pp. 212-30. 

 t Loc. eit. 



